In the past tea buds were plucked individually by hand, an expensive slow method of harvesting tea. Mechanical tea harvesters subsequently were developed, but all suffered from various differences, such as low capacity, inefficiency, etc. Such tea harvesters, in common with harvesters of other types of crops, e.g. grain, asparagus or the like, used a sickle or cutter bar having a reciprocating toothed cutter blade, to clip the harvestable shoots or buds from the tops of tea plants, and an airstream of some sort to convey the clippings to a collecting device. Examples of such harvesters for other types of crops or grass are disclosed in the following U.S. Pat. Nos.:
Miller, 3,193,995, July 13, 1965 PA1 Quick 3,555,790 Jan. 19, 1971 PA1 Hatton 3,665,687 May 30, 1972 PA1 Porter 3,760,573 Sept. 25, 1973 PA1 Quick 3,828,531 Aug. 13, 1974
All such harvesters suffered, however, from various deficiencies, as pointed out above, and cannot provide efficient practical harvesting of tea, taking into account the necessity of maintaining a correct cutting height for the cutter bar.
A grain harvester that has a stripping cylinder in contrast to a cutter bar, and provides for vertical adjustment of the cylinder, is disclosed in the patent to Engle, U.S. Pat. No. 1,122,375, Dec. 29, 1914, while the patent to Winger, U.S. Pat. No. 3,527,031, Sept. 8, 1970, shows a field crop harvester having a vertically adjustable cutter bar. Again, however, the Engle and Winger harvesters are impractical for harvesting tea or similar agricultural crops.